The constructor previously rejected auxiliary columns (+col) for all
non-flat index types. Analysis confirms all code paths already handle
aux columns correctly — aux data lives in _auxiliary shadow table,
independent of the vector index structures.
Remove the three auxiliary column guards. Metadata and partition key
guards remain in place (separate analysis needed).
Adds 8 snapshot-based tests covering shadow table creation, insert+KNN
returning aux values, aux UPDATE, aux DELETE cleanup, and DROP TABLE
for both rescore and DiskANN. IVF aux verified with IVF-enabled build.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
vec0Update_UpdateVectorColumn writes to flat chunk blobs but does not
update DiskANN graph or IVF index structures, silently corrupting KNN
results. Now returns a clear error for these index types. Rescore
UPDATE is unaffected — it already has a full implementation that
updates both quantized chunks and float vectors.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Add inverted file (IVF) index type: partitions vectors into clusters via
k-means, quantizes to int8, and scans only the nearest nprobe partitions at
query time. Includes shadow table management, insert/delete, KNN integration,
compile flag (SQLITE_VEC_ENABLE_IVF), fuzz targets, and tests. Removes
superseded ivf-benchmarks/ directory.
